1. Field of the Invention
The present invention relates to an imaging apparatus having a photoelectric conversion element package and a mechanism to adjust an inclination to an optical axis orthogonal plane (a plane orthogonal to an optical axis) thereof, and in particular, relates to an imaging apparatus configured to dissipate heat of a photoelectric conversion element package.
2. Description of the Related Art
In an imaging apparatus such as a digital camera, necessity to align a light receiving surface of a photoelectric conversion element with an image forming plane of a photographic lens optical system with higher precision is generally increasing with an increasing number of pixels in the photoelectric conversion element mounted inside the apparatus body.
Thus, an imaging apparatus is required to include a mechanism capable of adjusting the position of a photoelectric conversion element relative to a lens barrel.
Therefore, a conventional imaging apparatus is provided with a fixing member to regulate the position of a photoelectric conversion element package in an optical axis direction of the lens barrel. Then, after the photoelectric conversion element package is fixed to the fixing member, a relative position in the optical axis direction between the lens barrel and the fixing member is fine-adjusted. This allows alignment of the light receiving surface of a photoelectric conversion element with the image forming plane of a photographic lens optical system with higher precision.
Further, the reduction in total thickness of a photoelectric conversion element package, a fixing member, and a printed circuit board on which the photoelectric conversion element package is mounted has been desired to make an imaging apparatus smaller and thinner.
Thus, a conventional imaging apparatus uses a leadless-type photoelectric conversion element package. Moreover, as illustrated in FIGS. 1 and 7 in Japanese Patent Application Laid-Open No. 11-261904, a proposal is made to regulate the positions of a photoelectric conversion element package and a fixing member by arranging a printed circuit board between the photoelectric conversion element package and the fixing member.
In recent imaging apparatuses, heat generated by a photoelectric conversion element increases with an increasing processing speed of the photoelectric conversion element, thus causing a temperature rise of the photoelectric conversion element. Noise caused by a dark current of a photoelectric conversion element generally increases with a rising temperature and thus, it is required to reduce or suppress the rise in temperature of the photoelectric conversion element to achieve high quality of photographed images.
To address this issue, Japanese Patent Application Laid-Open No. 2003-204457 discusses an imaging apparatus provided with a mechanism to cause dissipation of heat generated by a photoelectric conversion element to suppress the rise in temperature of the photoelectric conversion element.
However, a conventional imaging apparatus includes an inclination adjustment mechanism capable of making inclination adjustments of a photoelectric conversion element relative to the optical axis orthogonal plane of the lens barrel. The inclination adjustment mechanism has a fixing member to regulate the position of a photoelectric conversion element package in the optical axis direction arranged on a rear surface of the photoelectric conversion element package.
An imaging apparatus including such an inclination adjustment mechanism has the fixing member halfway through a heat dissipation path to dissipate heat from the photoelectric conversion element.
The fixing member is configured to be in point contact with the photoelectric conversion element package via protruding portions to regulate the position to the photoelectric conversion element package. Thus, in this structure, a portion of the heat dissipation path to dissipate heat from the photoelectric conversion element transmits heat only through the protruding portions in point contact and thus, the efficiency of heat dissipation of the photoelectric conversion element may decrease.
Moreover, when heat from the photoelectric conversion element is dissipated via the fixing member, it is required to configure the fixing member so that the function to make inclination adjustments to the optical axis orthogonal plane of the lens barrel of the photoelectric conversion element does not become impaired. Thus, when heat from the photoelectric conversion element is dissipated via the fixing member, it is difficult to construct a robust heat dissipation path.